This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. During the reporting period our laboratory focused on the in vivo and post-mortem analysis of the volume and lateralization of the inferior frontal gyrus (IFG) (the homolog to Broca's area) in chimpanzees. We found that the IFG as measured form magnetic resonance images corresponds well to the cytoarchitectural distribution of Brodmann's area 44 (BA44) but not Brodmann's area 45 (BA45) cells. Thus, the IFG is the homlog to only one cellular portion of Broca area. BA 45 cells appear to localize in the gyrus immediately anterior to the fronto-orbital sulcus. Probabilistic maps of BA44 and BA45 were created based on the cellular data and applied to segmented grey matter volumes in a sample of 48 chimpanzees. We found significantly leftward asymmetries for BA44 and significant rightward asymmetries of BA45. Moreover variation in the asymmetries of BA45 were associated oro-facial motor control in the chimpanzees.